Folding machine



F. H. GIFFORD FOLDING MACHINE Sept. 5, 1933.

Filed July 30, 1931 zig Patented Sept. 5, 1933 UNITED STATES PATENT oFFIcE FOLDING MACHINE Application July 30, 1931. Serial No. 554,017

8 Claims.

This invention relates to folding machines and is herein illustrated as embodied in a machine particularly Well adapted to the production of round-cornered bookcases.

A machine having mechanism for folding round corners is shown in United States Letters Patent No. 1,776,390, granted September 23, 1930 upon an application filed in the names of Perley R. Glass and James E. Mclntire, that folding 10 machine comprising a work support to receive the corner portion of a bookcase having roundcornered boards, a folder movable over the support to fold the corners at the margin of a cover over the corners of the boards, and a forming block which cooperates with the folder. During the folding operation, the previously-bent-up margin is gripped frictionally between the folder and the forming block which thereafter move together in the same direction to lay the margin of the cover over upon the board, the margin being drawn progressively between the folder and the block during the folding operation.

During this operation puckers are formed in the margin of the cover, since the rounded corner of the board is convex, these puckers being finally flattened against the board to form plaits; and this puckered, and therefore eXtra-thick, portion of the margin must be drawn with the rest of the margin between the folder and the forming block.

In order to facilitate the passage of the margin, whatever its thickness in its puckered portions, between relatively movable cooperating members such as a folder and a block of the general type referred to, one of said members is provided, in accordance with the present invention, with a yielding portion. In the illustrated construction this portion is a coiled spring which extends around the curve-cl front of a forming block and. overhangs the base thereof With this construction the double thickness of the margin, which arises by reason of the puckering of the margin during the folding operation, may be drawn more readily between the folder and the block; and, at the same time, the separate coils of the spring crease the margin at closely adiacent localities so that the plaits, which result when the margin has been completely folded over upon the boards, are small and evenly spaced.

This and other features of the invention, including certain details of construction and combinations of parts, will be described as embodied in an illustrated machine and pointed out in the appended claims.

Referring now to the accompanying drawing,

Fig. 1 is a perspective of a portion of a machine in which the present invention isembodied;

Fig. 2 is av View principally in section showing a piece of work in process of being folded and Fig. 3 is a perspective showing more particularly the forming block and the forming plate upon which it is slidable.

Before setting forth the new construction in detail, the old construction will be brieiiy described. The machine comprises a generally triangular support 5 having a rounded corner, the convex curvature of which corresponds to the curvature of the rounded corners of the boards of the bookcase. An edge guide 7 hasstraight 70 edges which meet in a concave curve, said edge guide thus tting around the front and sides of the work support. A partly-iinished bookcase comprising two round-cornered boards and a flexible cover, the margin of which extends be- ,yond the boards, is presented to the machine with one of its corner portions resting upon the work support 5 and with the margin of its cover extending over the edge guide 7. A carrier 9, pivoted at a point not shown, is brought down to cause a thin flat presser 11 and a forming plate 13 to push the case down firmly upon the work support and to depress this support some- Y what so as to cause the margin of the 'cover to be bent up by the edge guide 7. The presser 11 85 is carried by two arms 15 which are fast to the carrier 9. The forming plate 13 rests at its rear end upon the presser l1 and is slidable with respect to it, said forming plate being carried by a bracket 18 fast to the outer end of a rod 19 90 which is slidable in a cylindrical bearing in the carrier 9. Also mounted on this bracket 18 is a forming block 2l which is slidable on the forming plate, said block being normally held in, the position shown by a coiled spring 23 and a 95 stop nut 25, but being capable of being moved to the right (Fig. 2) as will presently appear. A slidably mounted folder 27, having a recess in its forward edge shaped to fit about the rounded nose of the forming block, Ais moved forward at the proper time and has an abutment 29 which contacts with the end of the slidable screw 31 and pushes the screw, and with it the forming block, to the right during the folding operation. The work support 5 is yieldingly mounted for Ver- 105 tical movement in a casting 33 which may be raised at the proper time to press the fold against the underface of the folder.

The parts of the machine normally occupy the positions shown in Fig. 1. The corner portion of a partly finished bookcase is placed upon the work support, and the carrier 9 is swung down, as has Vbeen described, to bend up the margin of the cover. The folder 27 then moves to the right (Fig. 2). During the first part of the movement, theY margin at the corner of the cover 100 is gathered about the rounded corner of the board 200 as well as about the curved end of the forming plate and that of the folding block, as shown in Fig. 2. As the folder continues its movement to the right, the forming block and the folder move in unison, with the margin gripped frictionally between them so as to pull the margin tightly about the edge of the board and over the folding plate, the margin thus being progressively drawn between the opposed faces of the folder and the folding block until the fold is completed. The folding plate v13 is then withdrawn from beneath the folded-over margin; and the casting 33 is pushed up slightly to press the fold. Thereafter the parts return to the positions shown in Fig. l. No further description of the construction and operation of 'the machine as thus far described will be given, reference being made to the patent.

When the folder moves forward to the position shown in Fig. 2, it gathers the corner of the margin of the cover about the curved nose or forward end of the forming block and thus produces puckers in this margin which are later laid down upon the board as plaits. It is very desirable that the puclrers and the resultant plaits should be as narrow and as evenly spaced as possible so as to produce a finished cover which shall not be bunchy at the corners. t is also desirable, owing to the fact that the puclrers produce extra thicknesses in the margin of the cover, that one of the members which engage the margin should have a yielding portion to permit the eXtra-thick parts of the margin to be drawn readily between them during the folding operation.

In the illustrated construction a' small coiled spring 35 is fastened to the stem of and forms part of the forming block. This spring extends along the curved front and sides of the bloei; above and projecting somewhat outwardly over the b se thereof, being held in place by a screw 37.

When now the folder moves to the right (Fig. 2) to fold the previously bent-up margin over the rounded corner of the board, the margin is rst frictionally gripped between the folder and the rounded nose and sides of the forming block in the manner shown in that figure, with the upper portion of the margin in engagement with the coiled spring 35. As the folder continues its movement to the right, the margin is progressively folded and at the same time is drawn be`- tween the folder and the block, During this operation, the coils of the spring cause the forniation of small evenly-spaced puckers in the under folded part of the margin which are pressed down progressively into plaits by the folder; and the vspring yields to thiol; portions of the puckered margin so that said margin is readily drawn between the folder and the folding block 30.

Although the invention has been set forth as embodied in a particular machine in which the yielding portion of the forming block is a spring, it should be understood that the invention is not limited in the scope of its application to the particular machine or to the particular yielding member which has been shown and described.

Having thus described my invention, what I claim as new and desire to secure by Letters Pat ent of the United States is:

i. d machine of the class described having, in cor. ation, a work support, relatively movable cooperating members for engaging the margin of a cover and folding it over a board, one of said members being provided with a worl; engaging part of yielding material to permit the margin to be drawn readily between the members.

2l. A machine of the class described having, in coin nation, a work support, a folder movable over the support, and a forming block movable with the folder during the folding operation, said forming block having a resilient portion in contact with the work during the folding operation.

3. A machine IV'ne class described having, in combination, a work support, a folder movable over the support, and a forming blochmovable with the folder during the folding operation, said forming block having a resilient portion located above the base thereof and in contact with the work during the folding operation.

d. A machine of the class describedhaving, in combination, a work support, a folder movable over.` the work support, and a fo ming block adapted to cooperate with the folder, said forming block having a rigid portion lying in the path of the folder and an upwardly and outwardly flaring resilient portion.

5.. A machine of the class described having, in combination, a work support, a folder movable over the worlr support, and a forming block adaptedto cooperateV with the folder, said forming block having a rigidY portion lying in the path of the folder and a coiled spring located above the rigid portion, said rigid portion and said coiled spring being adapted to engage the work during the folding operation.A

6. A machine of the class described having, in combination, a work support, a forming plate, a folder movable over the forming plate, and a forming block adapted to cooperate with the folder, said forming block having a rigid rounded portion lying in the path of movement of the folder and an upwardly and outwardly flaring resilient portion.

7. In a machine of the class described, a forming block having a base provided with a rounded nose of rigid material, and a member of resilient material extending along the front and sides of the bloei: and projecting beyond the lower portion thereof.

8. In a machine of the class described, a form-` ing block havinga base provided with a rounded nose of rigid material, and a coiled spring extending along the front and sides of the block above the levelrof the nose thereof.

FLOYD H. GIFFORD. 

